3. Security [Intro over veiligheid en intrinsieke eigenschappen] 3.1 Structural attack resistance [sybil attacks] [double spending attack] [replay attack] [whitewashing] 3.2 Network attack resistance [Onion routing -> endpoint uncertainty] [spoofing] [MITM] 3.3 Reputation mechanism [tamper proof traffic graph] [transitive trust] [self sovereign identity]